Paper-pulp-recovery apparatus



S. MITCHELL PAPER PULP RECOVERY APPARATUS INVENTOR. j 'AJ-m4,. y' ATTORNEYS.

led oct. 1o, 924

Patented l0d.. 19, 1926 SIDNEY MITCHELL, 0F NEW YORK, N. Y.

PAPER-PULP-RECOVERY APPARATUS.

Application filed October 10, 1924. Serial No. 742,782.

"lhis invention relates, generally, to a novel means for recovering pulp from the waste water discharged from paper making machines, or for recovering other substances suspended in a liquid Where such operation is desired in connection with any other kind of apparatus, or in any other industry.

.For example, in the operation of paper making machines, wherein water is used to flow pulp to and upon the wire belt or other paper forming element, said water, both in draining away from the wire or other forming element and when removed by suction-boxes, carries with it a considerable quantity of pulp, and various attempts have been made to recover, or, in other words, to prevent loss of, the free pulp discharged with the waste water; such as by providing boxes or tanks called save-alls into which the waste water' containing pulp is collected, and from which only a part of such pulp charged lWaste `Water may be directly recirculated through the paper machines,- the remainder being Wasted. It is the object of this invention to provide an improved save-all apparatus into which the waste water containing free pulp is collected, and through which it'is passed in such manner that substantially all' of its pulp content may be precipitated and separated therefrom, and the separated pulp removed and returned to beaters, Jordans or back to the pulp chests of paper machines, and the clear water returned back to the clear Water chests of paper machines, thus economizing both pulp and water.

This invention has for a further object to provide a novel construction of save-all apparatus in which the flow of waste Water containing pulp is so controlled that substantially all a 'tation is eliminated whereby the centaine `pulp particles or fibers may settle or precipitate to t-he bottom of the main tank `of the apparatus, to be continuously removed by a novel mechanical scraping conveyor to' a pulp sump, while only clear water is discharged from said rmain tank; the separated pulp being finally removed from'the sump by pumping the same therefrom for delivery as may be desired to beaters, Jordans or pulp chests of paper machines.

Other objects of this invention, not at this are subject to such variation as time more particularly enumerated, will be clearly understood from the following dctailed description of the same.

With the various objects of my invention in view, the same consists in the novel paper pulp recovery apparatusv or save-all or the like hereinafter set forth; and, furthermore, the invention consists in the novel arrangements and combinations of the various devices and parts, as well as in the details of the construction of the same, all of which Will be hereinaftermore fully described, and then finally embodied in the claims appended to this specification.

While the objects of this invention as above stated, as well as the subsequent description of the same, deal with a pulp saving and Water clarifying apparatus for use, more particularly, in the paper manufacturing industry, it will be understood that my invention is not intended to be thereby confined to such specific use, but rather it is intended that my invention, as described and claimed, shall cover any industrial use to which the apparatus may be put in carJ rying on an operation of separating suspended substances from a liquid and at the same time clarifying such liquid.

The invention is clearly illustrated in thev accompanying drawings, in which Figure l is a plan view of the novel paper pulp recovery apparatus or save-all made according to and embodying the principles of this invention; and Figure 2 is a longitudinal vertical section through the same, taken on line 2-2 in said Fig, l.

Similar characters of reference are eniployed in all of the above described views, to indicate corresponding parts.

Referring now to said drawings, the reference character 3 indicates a tank or vat made of any suitable material and of suitable depth and len th; preferably, the tank or vat possesses a epth of five to six feet, a width of eight feet or more, and a length of one hundred to one hundred and fiftyfeet, although theseillustrative dimensions deemed advisable. The said tank Ior vat-is' provided at one end with an intakea-chamber' or sectioniv separated from thermain'ibody of the' tank or vat by a series of: transversely disposedmay be of any suitable construction. The

vertically staggered baiiles 5, over and under which the pulp charged waste water, delivered to said intake chamber or section 4 flows on its way into the main interior of the tank or vat 3. A suitable conduit 6 leads from the paper making machines to the intake chamber or section 4, for delivering the waste water collected from the paper making machines. The discharge end 7 of said conduit ma be of any suitable form, but is preferab y submerged in the water delivered into said intake chamber or section 4 so as to reduce the agitation of the entering water as much as possible. Formed in connection with the bottom of Said intake chamber or section 4 is a vsump 8, provided in a wall thereof with a clean-out opening 9 normally closed by a water-tight gate 1U urpose of said sump 8 is to collect sand an partcles of foreign substances which are carried into the intake chamber or section 4 by the waste water delivered' thereto.' Such sand and foreign substances being comparatively heavy, will gravitate into the sump and will thereby separate themselves from the waste' water and its pulp content before the latter enters the main body of the tank or vat -3. The sump may be periodically cleaned out by removing the gate 10 to giveaccess thereto.

llt is highly desirable that the pulp bearing waste water, delivered from the intake chamber or section 4, should enter the main interior ot' the tank or vat 3 with as little agitation as possible, so that a gentle, slow and quiet iiow of the water through the main interior of the tank or vat 3 may be attained, particularly avoidin eddies and comparativelylrapid currents 1n the depths or body otliti the water passing through the main tank or vat 3. To prevent undue agitation by the entering water, the receiving end of the main tank or vat 3 is provided with a catch-basin 11 supported by cross-bars 12 passing transversely from side wall to side wall of the tank or vat 3. rlvhis catch-basin 1l is of comparatively shallowT depth and is of less width than the width of the tank or vat 3, the same being alined with and having one side in contact with the lip 13 of the outer bams of the series of baiiies 5, so that water tiowing over the latter will irst enter the eatchbasin 11, and then gently overflow the remaining three sides of the latter into the .nain interior oit the tank or vat 3, thereby being delivered at the uppery level of the vater iiowing through the tank or vat with a Vmininnnn of consequent disturbance of the lower levels or depths of said water frowing through the tank or vat 3.

`Wit-h the like object of preventing undue agitation ot the water in the main interior oi thevtank or vat 3, at and adjacent to the point ort discharge et water trom. the

while at the same time drawing oi clear water from the upper levels thereof, I provide, adjacent to the opposite end of the tank or vat 3, an over-How basin 14-supported by cross-bars 15 passing transversely from side wall to side wall of the tank or vat. This over-flow basin 14 is of comparatively shallow depth, and is of less width than the width of the tank or vat, the same being located with its lips or margins slightly below the level of the water flowing through the tank or vat 3, so that the clear water from the upper level of the latter will overfiow into basin 14, to be thence Adischarged through a conduit 16 connected in communication with the interior of said basin so as to lead therefrom outwardly through the side of the tank or vat 3, and thence to such place as it may be desired to deliver clear water substantially free from pulp, as e g., to the clear water chests of paper machines.

Spaced longitudinall distant from the catch-basin 11 is a de ecting baie 17 extending diagonally across the tank or vat 3 with its lower edges submerged Slightly below the surface level of water flowing through said tank or vat 3. The purpose of this deflecting baffle 17 is to catch and deiect grease, scum or ioating substances which separate from the water flowing through the tank or vat and which rise to and collect 'upon the surface there-of. The scum, etc., thus caught by the baliie 17 is deflected and 4directed thereby to flow off through a discharge vent or opening 18 provided'in a side wall of the tank or vat 3, being thence conducted by a chute 19 or conduit to a suitable place of disposal.

Arranged to Aoperate in connection with the main Iinterior of the tank or vat 3 is an automatic pulp conveyor or scraper which moves the pulp that has been settled or precipitated out of the water to the bottom of the tank or vat 3, and thus conveys and deposits the same in a pulp collecting sump 20, which is provided in the bottom of the tank or. vat 3 at its discharge end. Said conveyer or scraper mechanism comprises a lower course oi" longitudinally spaced apart shafts 21, which are journaled to extend transversely from wall to wall of the tank or vat 3, and upon which are mounted, adj a.- cent to each side of the tank or vat, sprocket 'wheels 22; and, in like manner there is provided an upper course of similarly longitudinally spaced apart shafts 21', which are journaled to extend transversely from wall to wall of the tank or vat 3, and upon which are mounted, adjacent to each side of the tank or vat, sprocket wheels 22. Running over the vertically op osed sets of lower and upper. sprocket w eels 22 and 22', at each side of tank or vat, are endless oenveyer chains 23, to which are connected,

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so as to be moved by the chains, and so as to extend transversely therebetween at suitable intervals, a series of scraper blades 24. A suitable means fordriving the conveyer means thus provided may be afforded by mounting a drive pulley 25 on one of the shafts 2l,'which may be driven by a belt 26 from any desired source-of power, or the' conveyer means may be driven in any other manner or by any other power trans` mission means found convenient or desirable.

The operation of the conveyer means is such that its lower course so moves adjacent to the bottom of the tank or vat 3, that the scraper' blades 24 travel along the bottom toward the discharge end of the tank or vat 3, thus propelling the pulp, which has settled or precipitated out of the water to the bottom..v of the tank or vat, onward toward and finally into the collecting sump 20, as will be clearly understood from an inspection of the drawings. It will be understood that the conveyer means moves at a verv slow speed, so as not only to give ample time for the pulp particles lto settle out of the water to the bottom of the tank or vat 3, but so as to also prevent, by its movement, undue agitation of the water likely to disturb the settled pulp to such an extent as might cause the same to rise from the bottom of the tank or vat and again intermingle with the water.

The pulp which has been deposited in the collecting sump 20, may be withdrawn there-v from for delivery to pulp beaters, Jordans or directly back to pulp chests of paper machines, by means of a suitable pump 27 having its intake pipe 28 communicating with the interior of the collecting sump 20. The pump 27 may be of any suitable type, although I have found in practice that a rotary pump, such as indicated in the draw-V ings.l is very satisfactory, and may be conveniently driven by an electric m'otor 29 and belt or similar transmission 30, or by any other. suitable power transmission means.

In operation, the waste water, accompanying which is a considerable quantity of pulp, is first delivered into the intake chamber or section 4` at which place any accompanying heavy foreign substances are separated therefrom by gravitation into the sump 8. The series of baflies' 5 serve to retard the water and subdue the agitation thereof before the same is admitted into the main interior of the tank or vat 3, which effect is further aided by the catch-basin ll, so that the pulp bearing water is quietly introduced to the interior of the tank or vat 3 at the surface of the water level therein, so as to permit the slow steady and comparatively unagitated flow of the pulp bearing' water through the length of the tank or vat 3. The pulp bearing water thus moving slowly and quietly through the interior of the tank or vats affords the necessary conditions whereby opportunity is given for the particles of I basin 14 is clean and clear, and in condition for delivery to the clear water chests of paper machines.

I am aware that some changes may be made in the general arrangements and com'- binations of the several devices and parts of my present invention, as well as in the details of the construction of the same without departing from the scope of the invention as set forth in the foregoing specification and as defined in the claims appended hereto. Hence, I do not limit my invention to the exact arrangements and combinations of the devices and parts as described in said specification, nor do I confine myself to the exact details of' the construction of said parts as illustrated in the accompanying drawings.

I claim 1. In apparatus of the kind described, the combination with a tank of means subdividing one end of the tank to provide an intake chamber, means communicating with said intake chamber for delivering pulp bearing waste water thereto, a catch-basin in the receiving end of the main interior of the tank to receive the pulp bearing waste water from said intake chamber and overflow the same with a minimum of agitation into the main interior of said tank, a pulp collecting sump adjacent to the discharge end of said tank, an over-flow basin to receive clear water from the upper water surface level of said tank, a clear water discharge conduit communicating with said over-flow basin, a traveling conveyer means cooperating with the bottom of said tank for moving pulp settled out of the water and depositing the same in said pulp collecting sump, and means for discharging pulp from said pulp collecting sump.

2, In apparatus of the kind described, the

combination with a tank of means subdividing one end of the tank to provide an intake chamber, means communicating with said intake chamber for delivering pulp bearing waste water thereto, a sump communicating with the lower end of said intake chamber to receive gravitatable foreign substances for separation from said pulp bearing waste water, a catch-basin in the receiving end of the main interior of the tank to receive the pulp bearing waste water from said intake chamber and overflow the same with a minimum of agitation into the main interior of said tank, a pulp collecting sump adjacent to the discharge end of said tank, an overow basin to receive clear water from' the upper Watex` surface level of said tank, a clear Water discharge conduit communicating with said overflow basin, a traveling conveyer means cooperating With the bottom of said tank foi1 moving pulp settled out of the Water and depositing the same in said pulp collecting sump, and means for discharging pulp from said pulp collecting sump. Y

In testimony that' I claim the invention set forth above I have hereunto set my hand this 6th day of October, 1924.

SIDNEY MITCHELL. 

